Some blender newbie problems
He is probably duplicating some objects with Shift + D in the beginning. You can also add objects quickly with keyboard - for example pressing Shift + A followed by M and M one more time will go through Add Menu then Mesh and then Monkey, you can type that quite fast. You can see the letters coresponding to the menu items in the menus underlined:

It's possible to create custom shortcuts for something that you do a lot as well.
If the object is constructed out of a lot of objects joined in sculpting, some sort of re-meshing is usually used to make a continuous surface that you can sculpt: